Oh also, one other thing to bear in mind is QR does use married segment logic so if you search for CDG - HKG you will sometimes see availability you can’t see by searching for CDG-DOH and DOH-HKG separately.
I wonder if there is some sort of redemption policy change coming generally - a few days ago I saw Qx2 seat availability on a LHR-DOH sector in F which technically is not possible currently! (Could have been an IT glitch, I suppose).